imdb_data['plot_keywords'] = imdb_data['plot_keywords'].apply(lambda x: x.replace('|',' ').lower() if x == 'nan' else ' ') code example

Example 1: replace nan in pandas

df['DataFrame Column'] = df['DataFrame Column'].fillna(0)

Example 2: how to replace nan with 0 in pandas

df['product']=df['product'].fillna(0)
df['context']=df['context'].fillna(0)
df